Analysis of the composition of particles in gaseous atmosphere may be required in various occasions. For example, it is known that various particles in the earth's atmosphere have major impact to the climate. In addition of giving information regarding the impact of particles to the climate, an appropriate analysis can be used to monitor, for example, air quality, existence of chemical and biological weapons, drugs, emissions e.g. from industry and vehicles, and other particle type materials such as viruses, bacteria and so forth.
Analysis of particles can be based on various techniques. For example, mass spectrometry is widely employed in chemical analysis of particles. The samples for the analysis may be, for example, liquid samples, gas samples, particles in gas, particles in liquid, solid samples, samples of biological material such as molecules, bacteria and viruses and so forth.
Analysis of chemical composition of particles is typically, although not necessarily, performed by a specific analysis instrument. To be able to analyse particles by the instrument it is typically necessary to disperse a solid, bulk volume of particles to separate out the particles from the medium where they are floating and then collect the particles in preparation for subsequent analytical procedures. In a known arrangement, samples are introduced to a vacuum analysis chamber by pushing a rod which has the sample in the other end manually through a sealing element (vacuum lock). The sample is collected onto the rod from a gas outside the chamber where after the rod is pushed into the analysis chamber.
A possibility is to let gas or other flowing material to flow through the analysis chamber and try to hit to the particles therein by a laser beam. The flow into the analysis chamber can be controlled by opening and closing in a pulsed manner an appropriate valve arrangement in the inlet to the chamber.
A problem with the prior art has been the lack of automation in the introduction of samples to a vacuum analysis chamber. Instead, the samples need to be introduced manually. A problem relates to the lack of possibility of collecting samples and analysing them substantially in real time and/or in a continuous manner. More particularly, if a sample is collected beforehand, such as by means of the above mentioned collecting rod, and because of the time it takes before the sample can be analysed, a chemical composition of the sample may change, which may affect the outcome of the analysis. Furthermore, there is a need for general improvements in the sample collection process in view of the effectiveness, performance and controllability of sample collection.